Machine for grinding blades of lawn-mowers.



Patented Jan. 30, I900.

C. R. ZACHARIAS.

MACHINE FOR GRINDING BLADES 0F LAWN MDWEBS.

(Application filed Aug. 14, 1899.)

4 Sheets-Sheet I.

(No Model.)

Patented Jan. 30, I900.

6. B. ZACHARIAS. MACHINE FDR GRINDING BLADES 0F LAWN MOWERS.

(Application filed Aug. 14, 1899.)

4 Shaet8-Sheet 2.

(No Model.)

M w W No. $42,275. Patented Jan. 30, I900.

C. R. ZACHARIAS.

MACHINE FUR GRINDING BLADES 0F LAWN MOWERS.

(Application filed Aug. 14, 1899.)

( D 4 Shady-Sheet 3.

z W V luuenroz No. 642,235. Patented Jan. 30, I900. G. R. ZADHARIAS.

MACHINE FOR GRINDING BLADES 0F LAWN II OWERS.

(Application filed Aug. 14, 1899.) (No Model.) @Shee'tv-Sheet 4.

H L 0 1 v 6 0 H a 3 1 1 7 uwenroz Q g i w m Y. W a a w aw NZ m W Y Q 1 2 WM r 6 IE Q m w il 1 UlTFD STATES PATENT OEEIQE.

ouAnLEs R. ZACHARIAS, or ASBURY PARK, NEw JEEsEv.

ACl-lllNlE FOR GRINDING BLADES OF LAWN-MOWERS;

SPECIFICATION forming part of Letters Patent No. 642,275, dated January 30, 1900'. Application filed August 14, 1899. Serial No. 727,198. (No motlelil T (Ir/Ll, 7071/0710 ('6 717/661] concern:

Be itknown that LCHAELEs R. ZACHARIAS, a citizen of the United States, residing at Asbury Park, in the county of Monmouth and State of New Jersey, have invented certain new and useful lin provementsin Machines for Grinding the Blades of Lawn-Mowers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to machines for grinding mower-knives and cutters of kindred nature and for sharpening edged tools generally requiring to be either hollow or edge ground. The device is, more properly speaking, a holder for the work and is susceptible of a variety of adjustments to meet the various forms of cutters, tools, and the like requiring to be sharpened and is mounted to reciprocate and carry the work back and forth in front of the emery or other grinding wheel. Combined with and forming an essential part of the device is a rest having members disposed upon opposite sides of the emery-wheel to prevent jumping of the work and cause the parts to run steady and with even movement.

Fora full description of the invention and the merits thereof and also to acquire a knowledge of the details of construction of the means for effecting the result reference is to be had to the following description and the drawings hereto attached.

\Vhile the essential and characteristic features of the invention are necessarily susceptible of modification, still the preferred embodiment of the invention is illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of the machine. Fig. 2 is a top plan .view, the dotted lines indicating the rotary cutter of a lawnmower in position. Fig. 3 is a transverse sec tion on the line X X of Fig. 2. Fig. 4; is a transverse section on the line Y Y of Fig. 2, looking to the left, showing the relation of the knife and the parts when hollow-grinding. Fig. 5 is a section on theline Z Z, looking to the right, showing the disposition of the parts when grinding the straight edge of a knife. Fig. 6 is a front view of the guide and rest for the knives. Fig. 7 is a plan section about on the line W W of Fig. 0. Fig. 8 is a detail section of an arm about on the line V V of Fig. 2. 7

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

The work-holding means are mounted upon a carriage which is adapted to reciprocate in front of the emery-wheel or grinding device. The carriage consists of a plate 1, having ter-' minal bracket-lugs 2 at one edge and a me dial bracket 3 at the opposite edge, grooved rollers 4: being journaled upon axles or pins applied to the said bracket-lugs 2 and 3. Rails 5 and 6 are disposed in parallel relation and are spaced apart the requisite distance to receive the grooved rollers 4, which are adapted to travel thereon. The rail 5 is considerably longer than the rail 6, because of the relative position of the grooved rollers applied to the terminal bracket-lugs 2. The rails 5 and 6 constitute a track for the carriage to travel upon when the machine is in active operation, said rails being secured to a bed or base '7, which may be a table, bench, or other suitable support. A rod or shaft 8 extends lengthwise of the plate or carriage and is mounted in terminal slides 9 and a medial slide 10, said slides bein mounted upon ways or planed ribs projecting upward from the surface of the plate 1 and disposed transversely thereof in parallel relation. The slides are approximately of like formation and are composed of bearing-heads 11 and shanks 12, thelatterhavinglongitudinal slots 13,through which pass clam p-bolts or machine-screws14, by means of which the slides are secured to the plate 1 in an adjusted position,washers 15 being interposed between the heads of the fastenings 14 and the upper sides of the shanks 12, so as to secure an extended bearing thereon. The medial slide 10 is confined between collars 16, secured to the rod or shaft 8 and having their inner sides touching the ends of the bearing-head. This disposition of the parts prevents relative longitudinal play or movement of the rod or shaft 8 and the parts applied thereto. The terminal slides 9 have positive means applied thereto for moving them transversely of the carriage in order to advance the cutter or knife to the grindingwheel as the sharpening process is, carried on. As shown, lugs 17 project vertically from the plate 1 and are transversely apertured to receive adjusting-screws 18,which are mounted in said lugs to turn freely forward or backward and which are incapable of longitudinal movement. These adj Listing-screws 1 8 have screw-thread connection with the adjacent ends of the slides 9, and each is provided at a point between its ends with a shoulder'or collar 19 to engage with the inner side of the lug 1 7, the outer or projecting end of the-adjusting-screw being threaded to receive the hub portion of a hand-wheel 2O, which is interiorly threaded, so as to screw upon the threaded end of the part 18. The lug 17 is held between the shoulder or collar 19 and the inner end of the tubular or hub portion of the hand-Wheel. In the event of the parts 17 1 9 and the hub portion of the hand-Wheel varying so as to permit an appreciable play of the terminal slide the hand-wheel can be turned so as to compensate for wear and prevent any looseness or relative movement of said parts, therebyinsuring accurate adjustment of the slide in accordance with the scalegraduations presently to be described. The hand-wheels 20 when properly adjusted upon the outer threaded ends of the adjustingscrews 18are made fast by means of jamnuts 21, mo'unted upon the threaded terminals of the parts 18. When it is required'to adjust either one of the hand-wheels to allow for wear and take up looseness, it is necessary to first loosen the jam-nut, after which the hand-wheel can be moved forward, so asto grip the lug 17 between the shoulder 19 and the inner end of the tubular part of the handwheel, care being observed not to grip the lug with such force as to prevent free rotation'of theadjusting-screw in order to admit of a positive movement of the slides transversely of the carriage.

The position of the-track and emery-wheel or grinder remains fixed. Hence the carriage travels in a direction parallel with the axis of the grinder and at a fixed distance therefrom. In order that the cutter or knife may be advanced to the grinder, the work-holder means are mounted upon the carriage in such a manner as to move transversely thereof. The rod or shaft 8 has the work-holders applied thereto, and being mounted in the slides 9 and 10 is laterally shiftable by means of the adjusting-screws 18 in the manner previously stated. After the knife or cutter has been properly positioned with reference to the cooperating parts it can be advanced to.

the grinder in parallel lines with a measurable degree of certainty through the in.- strumentality of the scale-graduations 22, applied to the end portions of the plate 1 and extending transversely thereof, said scalegraduations cooperating with pointers 23, applied to the terminal slides 9. These scale- .graduations and pointers occupy a like relatixe position. Hence upon moving the slides 9 opening.

in such a manner that the pointers will indicate like graduations it will be made known that the rod or shaft 8 is parallel with a given or normal position. When it is required to adjust or shift the work-holder laterally of the carriage, it is necessary to loosen the clamp bolts or fastenings 14, and after the adjustment has been effected the rod or shaft 8 is fixed by retightening the clamp-bolts or fastenings 14.

The work-holders proper consist of arms 24 of like formation and of approximately C form, and inasmuch as these work-holders or arms are of duplicate construction a detail description of one only will be given. The lower member 25 of each of the arms is providedwith a jaw 26'at its inner end, having a vertical face'27 and a horizontal face 28, bothfaces being toothed or roughen'ed'to prevent slipping of the knife or cutter when clamped thereagainst. A sleeve 29 is formed'at the lower inner corner of the member 25and receives the rod or sh aft 8, which passestherethrough and upon which the armor work holder is longitudinally adjustable to vary the distance between the companion work.- holder, according to the length of the blade or cutter to be operated upon. The opening through the sleeve is recessed at a convenient point, preferably in the top side, and receives the inner end of a spring-clamp 30, the outer end of said clamp being bent at a right angle and secured to the end of the sleeve 29 by a machine-screw or like fastening. Thehorizontal member of'the spring-clamp is normally out of contact with the rod orshaft 8 and is adapted to be brought forcibly into engagement therewith to secure the workholder in an adjusted position by means of a clamp-screw 31 let into a three. ed opening formed in the side of the sleeve 29 opposite the recess in which the active portion of the spring-clamp 30 is fitted. Upon loosening the clamp-screw 31 the arm or work-holder can be shifted along the rod or shaft 8 and when movedto the required position is made fast by retightening the clampscrew 31, which causes the spring-clamp 30 to bear against the rod or shaft 8 with sufiicient force to prevent slipping of the work-holder in either direction.

A stem 32 is slidable in the opening formed through the lower member 25 of the arm 24 and is provided at its inner end with a jaw 33, movable toward and from the vertical face 27 of the jaw 26 The outer end portion of the stem 32 is reduced and threaded and receives a hand-nut 34, by means of which the stem is moved so as to advance the jaw 33 toward the fixed jaw 26 and clamp the knife or cutter placed between the two jaws. The stem 32 is adapted to slide freely in the opening formed through the part 25 an dis prevented from turning therein by having its inner portion made square or angular and cooperating with a corresponding part of the IIO The knife or cutter 35 isgripped between the fixed jaw 26 and movable jaw 33 and is held in an approximately vertical position and is advanced with its side against the peripheral portion of the emery-wheel or grinder 36, thereby producing what is commonly known as a hollow or concave grind.

The overhanging portion of the arm 24 is formed with a lug 37, through which operates a clamp-screw 38 in vertical line with the jaw 26 and is adapted to cooperate with the horizontal face 28 thereof, so as to grip the knife 35 when placed horizontally for the purpose of grinding the edge thereof in the ordinary manner. It will thus be seen that the jaw 26 is disposed in such a manner as to grip the knife in either a vertical or a horizontal position, according to the nature of the grinding. An approximately V-shaped notch or seat 39 is formed in the inner side of the head of each of the arms 24: and receives the terminals of the shaft or journals of a cylinder or rotary cutter, as indicated by the dotted lines in Fig. 2. In the event of the shaft being longer than the distance between the work-holding arms 2% when moved to their extreme outward limit upon the rod or shaft 8 provision is had for accommodating such cutter by forming an opening 40 in one of the arms and intersecting with the V shaped notch or seat 39. The end portion of the shaft can be passed through the opening 40 in one of the work-holdin g arms, thereby admitting of the opposite end of said shaft restingin the notch or seat 39 of the opposite arm.

In order to fix the position of the knife or cutter when acted upon by the grinder, a combined guide and rest is provided and consists of an angle-bracket 41, having its base longitudinally slotted at l2 to receive the lag or clamp screw 43, which is let into the bed or base 7 and serves to secure the bracket at an adjusted position. The vertical portion of the bracket terminates in a fork 44:, the members of which are parallel and terminate in horizontal extensions 45, which are vertically apertu red to receive the lower ends of adjusting-screws 46, swivelly mounted in slides 4-7, applied to the fork members. Each of the slides 47 is formed with a vertical slot 48, which receives a clamp-screw it), by means of which a slide is held in an adjusted position, and the upper end of the slides has a lateral projection 50 overhanging the horizontal extension 5 of the fork members and in which is fitted an adjusting-screw in such a manner as to turn freely or be incapable of independent longitudinal movement. Each adjusting-screw is formed with a shoulder or collar 51 to engage with the lower side of the lateral projection 50 and with acompanion collar 52, having screwthread connection therewith, the lateral projection 50 being secured between the fixed shoulder 51 and the adjustable collar 52. A binding-nut 53 is mounted upon the upper threaded end of the adjusting-screw and secures the adjustable part 52 in the proper position. In the event of the parts 50, 51, and 52 becoming worn to such an extent as to admit of the adjustingscrew having vertical play the binding-nut 53 can be loosened and the collar 52 set up, so as to take up the looseness between the parts, after which its position is fixed by screwing home the binding-nut 53. A pin 54 passes transversely through an opening near the upper end of each adjusting-screw 46, and the projecting end portions of the pin are adapted to enter notches in the lower end of a wrench or crank 55, provided for rotating the adj Listing-screw, so as to move the slides 47 either up ordown, according to the required position of the rests carried thereby. The rests 56 consist of rollers mounted upon pins projecting from the slides 47 in an opposite direction to the lateral projections 50 and are adapted to come beneath the knife or cutter being sharpened, so as to support it againstthe action of the grinder. When sharpening a straight blade, knife, or cutter, the rollerrests 56 are adjusted so as to aline horizontally; but when sharpening a rotary or cylinder cutter, such as a lawn-mower, in which the blades or knives have a spiral formation, said rests must be adjusted so as to occupy different elevations, depending upon the pitch of the knives and according to the direction of deflection. The independent adjustment of the rests makes it possible to adapt them to various forms of cutters or knives, so as to provide a firm support therefor at each side of the emery-wheel. The emery-wheel or grinder 36 operates in the space formed between the members of the fork 44, with the rests 56 upon opposite sides of the plane thereof. This emerywheel or grinder may be mounted in any desired manner, and, as shown, it is secured to a shaft mountedin the usual head 57, which is secured to the bed or base 7 at one side of the angle-bracket 41. The precise manner of mounting the emerywheel is immaterial so long as the grinder operates in the space of the fork 44 and be tween the rests 5G.

The parts being assembled and disposed in about the manner substantially as herein set forth and it being required to grind the blades or knives of a cylinder or rotary cuttor-such, forinstance, as of a lawn-mowerthe same is placed in position with the end portions or journals thereof resting in the notches or seats 39 and with the blade to be sharpened placed upon the rollerrests 56. By a proper manipulation of the adjustingscrews 18 the work-holder means and cutterare advanced transversely of the carriage and toward the grinder. The knife orcutter in position to be ground is sharpened its entire length by reciprocating the carriage upon the track and afterone knife of the rotarycu tter is sharpened'the next succeeding knife is brought into position and the operation repeated until all the blades of the cutter are sharp- The parts when once adjusted form cued.

ground, the carriage being reciprocated as thegrinding progresses and the depth of the grinding being regulated by a lateral or transverse movement of the work-holders with ref- 'erence to the carriage through the instrumentalities herein described.

Adjustable steps 58 are applied to the bottom side of the lower members of the arms 24 and areadapted to come in contact with the plate 1 and fix the position of the arms with reference to each other prior-to securing them to the-rod or shaft 8. By adjusting the stops 58 in a like manner the arms 24 will aline and coincide longitudinally when turned to admit of the stops resting upon theplate 1. In this position the arms are secured to the rod or shaft 8 by means of the spring-clamps'30'and clamp-screws 31 in the manner set forth. After-the arms have been made fastto the rod or shaft the latter can be turned inthe bearing-sleeves of the slides 9 and ]0,*the clampscrew 59, applied to the medial slide 10, being first loosened. After the rod or shaft 8-has been turned to bring the work-holding arms to the required position with reference to a horizontal plane they are fixed by retightening the clamp-screw 59.

Having thus described theinventionywhat is claimed as new is- 1. Ina machine of the class set forth, the combination with the grinder and the workholder, of slides bearing rests to engage with the work upon opposite sides of the plane of the grinder, and means for independently adj usting the slides to vary the position of the rests, substantially as set forth.

2. In a machine of the typespecified and in combination with a work-holder and grinder, of a fork having its members extending upon opposite sides of the plane of the grinder, slides applied to the fork members and bearing rests, and means for independently connecting the slides with the for-k members in an adjusted position, substantially as set forth.

3. In a machine of the type set forth, and in combination with the Work-holder and grinder, a fork having its members extending upon opposite sides of the plane of the grinder, slides bearing rests and directed in their movements by the said fork members, and

means positively and adjustably connecting said slides with the fork members, as and for the purpose set forth.

4. In a machine of the character specified, a work-holder and a grinder, in combination with a fork having its members extending upon opposite sides of the plane of the grinder and formed with vertically-threaded openings, slides bearing rests and having adjustable connection with the fork members, and

adj usting-screws having swivel connection with the slides and screw-thread connection with the threaded openings of the fork members, substantially as and for the purpose set forth.

5. In a machine of the class set forth, and the combination with the work-holder and grinder, of a combined guide and rest comprising an angle-bracket adapted for adj ustable connection with the bed or base and havinga forked end, slides having adjustable connection with the forked members and provided withroller-rests, adj usting-screws swivelly connected with the slides and having screw-thread connection with the fork members, relatively-adjustable shoulders applied to the adjusting-screws and having portions of the slides embraced. between them, and means for independently operating the adjusting-screws, as and for the purpose set forth.

6. Ina machine of the class described, acarriage, slides transversely adjustable with reference tothe carriage, a rod or shaft supported by said slides, and a work-holderadjustable upon the said shaft and capable of independent angularadj ustment, substantially as-set forth.

7'. In a machine of the character set forth,

a plate, slides adjustable transversely of the plate, a rod or shaft mounted in the slides and adapted to turn with reference thereto, and work-holders independently adjustable on the shaft, substantially as described.

, 8. In a machine of the class set forth, a

plate, a rod or shaft, a slide intermediate of the ends of the plateand supporting said rod or shaft at a point between its ends, collars having adjustable connection with the shaft and located upon opposite sides of the said slide to preventlongitudinal movement thereof when adjusted, means applied to said slide for securing the shaft therein when turned in the required position, work-holders mounted upon the said shaft upon opposite sides of the aforesaid slide, and means for securing the work-holders in an adjusted position, substantially as set forth.

9. In a machine of the type set forth, a plate, end slides applied to the plate, means for adjusting said slides transversely of the plate, a rod or shaft supported by the slides, and work-holders adjustable on the said shaft, substantially as set forth.

10. In a machine of the character described, a plate, a medial and terminal slides applied to the plate and adjustable transversely thereof, a rod or shaft applied to the said slides, means cooperating with the medial slides and shaft to secure the latter against turning and longitudinal movement when adjusted, adjusting means between the terminal slides and plate, independent means for securing the several slides to the plate, and work-holders applied to the shaft and adjustable thereon, substantially as set forth.

11. In a machine of the class described, the

combination with the grinder, of supportingarms provided in their inner sides with seats substantially as set forth, one of the arms having an opening intersecting with the seat, as and for the purpose specified.

12. In a machine of the type set forth, a work-holding arm of approximately C form having its lower member provided with a jaw having approximately vertical and horizontal faces, a clamping device cooperating wit-h the arm to clamp the work against either face of the jaw, substantially as set forth.

13. In a machine of the variety specified, a work-holding arm of approximately C form having its lower member provided with a jaw having faces disposed relatively at an angle to each other, and independentmeans applied to the members of the arm to clamp the work against either face of said jaw, substantially as described.

14. In a machine of the type set forth, an arm of approximately C form having itslower member formed with an opening and a doublefaced jaw, a stem adjustable in said opening and provided with a jaw to cooperate with one of the faces of the fixed jaw, means cooper ating with said stem to advance its jaw and grip the work between said jaw and the opposing face of the fixed jaw, and a clampscrew applied to the terminal portion of the arm overhanging the fixed jaw and adapted to cooperate with the other face of said fixed jaw, substantially as and for the purpose set forth.

15. In a machine of the class set forth, the combination of a plate, a rod or shaft supported by said plate, work-holding arms applied to the shaft and adjustable thereon and provided with means for securing them in an adjusted position, and adjustable stops applied to said arms to come in contact with the plate to fix their position, substantially as set forth.

16. In a machine,snbstantially as described, a plate having an ofistanding portion, a slide, an ad j ustin g-screw having threaded connection with the slide and formed with a shoulder to engage with one face of the said oifstanding portion, a shoulder or stop having screw-thread connection with said adjustingscrew and adapted to engage with the opposite face of the aforesaid ofistanding portion, and a jam or binding nut for securing the adjustable shoulder or collar in the located position, substantially as set forth.

17. A machine of the character set forth comprising a combined guide and rest havin g portions extending upon opposite sides of the plane of the grinding-wheel and provided with independently-adj ustable rests, a reciprocating carriage, medial and terminal slides applied to the carriage, independent means for securing the slides to the plate in an ad j usted position, corresponding scale-graduations and pointers between the terminal slides and plate, means for adjusting the terminal slides transversely of the plate, a shaft sup ported by the several slides, work-holders adjustably mounted upon the shaft and consisting of approximately C-shaped arms having their lower members formed with openings and double-faced jaws, and means applied to the members of said arms to clamp the work against either face of the fixed jaw, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES ll. ZAOllARlAS. [n s] Witnesses:

J OsEPI-I A. IMLAY, JULIA DUNCAN. 

